SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5018c94adf6dd2ee33e9d77f76a75b46eef8c652d3acd724289b15912fb1d732' 
  AND token = 'wF9Ct4JKm/411LNJbgJgWHUCTDvZqzzlCSWg8I4BlaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

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