SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a1b28cce0b1d2af81d09c8cd1ab1f1aa222ef453eeb478b32d04f760275685b' 
  AND token = '9G9Zx2L/hznv1FigU+jaaB/K5AGb683UjnLdgQt+g/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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