SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab6453c4a8be9a0cdadb193ab919f6a9f344af7ec42c7cba0955264d68e277f2' 
  AND token = 's1vEoi9RuRpptyIBJYh0IiZZ0of2fwdBsDGcNTc21Hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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