SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '864512c11a75dbdf20a4f050ac373c81ccb936053b297c862473fd7ad1da1065' 
  AND token = 'N2LWjx+eGwhPqGGzTqAVH/a+eef/tsgb1QwRgaWlCG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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