SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '778286a28b123f4526b72dc15f88009194b6fde70f5cdb24ab6cc5906fbc039a' 
  AND token = 'N73k8NNlGMz/BzVKKtXnAhsOBLN36MvjS4VQoG7FaLs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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