SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '094eeae32c5e72cb25089589ef30746ee05315ecfb164415bd909f3384bde1e0' 
  AND token = 'B3tyg3hi7fGLuIpJ983kuTEBfbORd+fDLWLydNk347w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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