SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70750d467ab95cff6445e50bd72fb5e0396931c61ab169438fc17cf4c9c22de9' 
  AND token = 'l2NqxqcLF5ufWgXTuji3ME8x3vR0xz9bOUW4YjBNOxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}