SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a760bdc700f824d77b4a2c4ad5b5d8da5f1000c674addf70e86bd19236606d7' 
  AND token = 'cMCBORUrjrZo0ZcqQLb8boMAirCAFPWByKiur9ab2EE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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