SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca4eb54a294cf9266198ce6441be6bc5eb46eb84a2e0ca8b57f388803f356e09' 
  AND token = 'qEpz2Jarc2N5HvSQtWOCzD80/ocBAQU30qMVUEzaAKk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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