SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86a605eb7d7b0b4583af73269a3b9f1072011893bcb7c54ff5ac0d611f2e5c86' 
  AND token = 'qC+8VtR63kjZ3qzwCZas59xRjkqF7CrQB0K5I/lCjXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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