SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f5f9d452dd6a4528aad78e7d6d271e851a63450a8a241d6658b5bec3dc4c27dd' 
  AND token = 'd6Rd751+hNZNd4S/ldI7wdVN/A5DdhFNlfPSVYmQi3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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