SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71373ca20f7a1c2ee0b3801ae59df707d066c023e6829010ccd1a8815b985d6f' 
  AND token = 'NkLaOhIEjRQTZg0s1n2iHoWVciDgEex6OWYfwi2AhXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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