SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fea9441834cf59c7e5fbee5b6d958307ada29748205b6b93e7b657c2eab34e2a' 
  AND token = 'injoKbj8sCKWHljJotJcRuBUvfSQr2Z9DHirgqzhl1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}