SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fd31411b52adc5b9eb33c6f997d45f2e652096676627b54fca9a3bc7a2e9741' 
  AND token = 'O+RQYXiyyfnJI7CEO5HOTyJ0fmkdrV1JcHR00jQikEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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