SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a82f8ce3b2971a0930fae089322f5718dcfd43eeaa7027ad3e6ddb962311ca41' 
  AND token = 'QPhztrJmAqSbo4Q3GX8cms7qUTDRbAgnHTilFBzoUps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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