SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd1e0e97a3c7d513d9005a15ecbbf860aa8632dba27cbb4f9158fe8905fd908b' 
  AND token = 'bGLPHSKkmhRRy3mSLX2W0yW49rk1TFwXjZzWAFCwQpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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