SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e8b6562ab553266538d792e68103c622dab9101cca59c233800e6008660aa832' 
  AND token = 'lKlxz55s/1P4u5BxLT21xV7//hYDLFt6STF/rvQuxCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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