SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a55d0c3a0eb781e59628a3ba27a31203b54baf52ab390cd68addef632bb5647' 
  AND token = 'NmBnnlzApUhR069bEqOgsX2yZ3Uc3H1i+sQYTcsX57Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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