SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '304971d6742933735d5c1416d68f4ae2d3546acbc07cfa920609de566ea05092' 
  AND token = 'vY5khWoj7CPRoJenugduRixvYXEfPW75Hmu0ma+xi9s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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