SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '822d94c701abf976db4ca51bbdf2386a879b513254c16f974a4a599e88fb25f3' 
  AND token = 'stgf4yk7wo49EFmyUAEdu2K/zXpl/2bnyIuJTLxKuG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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