SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7de94b916693e2d6499996d69925951dabed555aabda6718dc67cdc6c04a1b80' 
  AND token = 'LMSEFJYpYuR3APfb+qxFzbp75HVH69SDa8fG9+TC/eM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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