SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52a2d2b7b421505537f2a40a7baee39b4d4d631e97e0844ea0c2c88e4341cb52' 
  AND token = 'Jcjr4Owo18VUz2tGeUvKvWZ+VuXcRg9vXzNQDUWq+PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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