SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c86db07b31486c697e70e7eac2387d6505134ed9d800d24dd148ed74ddd8c4aa' 
  AND token = 'wRJWsfxkQvpm5hgSx6hlrLFszz1ugQLkKBOWDqiP67g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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