SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a9deee4a28e4dae215553b984b9908c8ebc55fdcd755b2b7da0bf281d4911de' 
  AND token = 'q7QBJnePu4pG5cWfnZdVYFFZZfROgGIdonPFo9l+H+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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