SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abec5417d2e9d233d586895045d0043b94c2c692ffe172b0e8bc2380a5115a02' 
  AND token = 'pEiDDEV3Sa5aOdH5g7b14u7nIjOZoR5Eple86KoHm+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

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