SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e5f153a31ee84a4e73b6bd282172139168fb5ffb50e83aa31056caba4a9509c6' 
  AND token = '6Vv/SfAzvJVa1mfBHFEUSxALJKOG7yesWOISLBzIWcE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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