SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46cfa85e37f2bf9136779320ec6caf9d4a623750f29de1e1f3aee2068ee15e3d' 
  AND token = 'qvPgpywA9bbHSAv9f6BGU5yYGGUKJUyWCgC4YVX+Fv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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