SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce1deb34199f9e50f5b28c15c38546c0ad07ebdbe6c765c673b12c0282b204a1' 
  AND token = 'p/5gva5F41AjfeOcdsXN93s2UWMTQnZ6ysYehhg+NvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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