SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2df526a500c14fd9d97652017b4c64eef6694920547ff4030d2c7f5628717565' 
  AND token = 'JzYPns8ah/peUxhkFCHHZR3E2zWvVQ/Hhi5hiJCedjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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