SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37b508e47a8fed27b024dda9989da2a7a5b05ecc7f41df1b95f0dc7eb36a2b15' 
  AND token = 'LbPou8woAjGZj6o1hBKq6mzbT+/FwHtFzPU6Mu+87DM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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