SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91ba8f98ecfd6a7e2a40b61a254011d3bcf236a10bd3a4bea4b827833da8a7d5' 
  AND token = '5aWhFFadjvrZVSi1HIB1cqoOUydKEOAvMjgUSdqmepI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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