SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3490d84188e4ad8b28bd069959f2f7fd2fd83dc6e5c59b08c5abedf2c7610798' 
  AND token = 'QgwRFxJ8JD2fPYc/IIwoCq/7llhCQQBpaUpoP1DBBiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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