SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4adb01e7dc8f129dbdc17e531d0f7f90acdf584c3be8bd385c93d8167baf94d' 
  AND token = 'y/oErzllP3LetXff9cVuCoq1bPx+cwzZRvQIag0kvqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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