SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5afd1d78fa5db88dde50e54c7e23252b815a8fd2636c2c629765bf61eb8ec076' 
  AND token = 'wWx2w27s9eAGWNMoTS7hdvEbGl+LDt4olL0E6unGKlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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