SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f7dd5c75e7874243a1f6906e6afb5a2c461fb0f4784fa6bf6f5ff4eb47de4764' 
  AND token = 'Is8/ILnSzX2Y/bGXnrmldzMoU/OqK+V+EnGqSIBNzWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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