SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f1e060a51f0f98c25adc6428431fee545948620e3a5b31cc7b3aabc2884b25d6' 
  AND token = '+6RXqSFfpNQyVNNDw/oLQ4hIYd4huEnxYJZ3dkExi0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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