SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c3d509057094a07d6edda5141994b51d0e8f4c95ab4ab84cd7a8868179c4800' 
  AND token = 'KH5nwq6G7VuM8YB0F0s1i+DYhjNSEtaBSD1n16Vti5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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