SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd0959eac10bf4c2a1a72baf4c9653a4753ed743479abaef9943268314808e3f' 
  AND token = 'm2CJ5pOTaFpn+aUu2+hPWoAOfGhsAtR9NVUasYDuL7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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