SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06475cd39ac0b590e11d04b3e4072cb03d511ab0539bde337aa5a1f3d2bee9e2' 
  AND token = 'fwgALChwv7NCqMrBGoRjEltfiYWaL+Gfkk4BkTN131o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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