SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94cf40c286cf6bc6eb65f1bbe0822889d86f9772130a0254855804e33f02ac3d' 
  AND token = 'B2F7ivpGjNSXQDp0IZZaQgWhfJEhhmo71bb+zbK/ScU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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