SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '643ba583c8b847bc4249de1cd9571f874df349e1a7bc832b6a3499fc1682924e' 
  AND token = 'n9qR2ybJG6PLKrd8xJan1WPWEhdKHsy5B6aOihSO4PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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