SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9c7479f67087d795b4ae069cedd0a4a48a3736be6bd920c04289cb846f629a3' 
  AND token = 'MXodBH5CUJMyrnFpJfhpLR7ghmsvnK2Q0g1GR05evEk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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