SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '45b7255753cd37f3e5775f33a634153a8c8f2094ea91388f216ac7bd1b67cc76' 
  AND token = 'B+Gyu/pnnz8+RE4BC9rDS4VR/DF0/T3LnNTjJdvi41I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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