SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98988334b601ec0ec33ca1e27950e03ca2077a2b1dda686a3b3a2ad457588bac' 
  AND token = 'VaRPBuzZOzvU9yNwN8edC/qnijCsAnGRrDvOL1g+iYQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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