SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96ae5f24460f83c9711eb832bd14e9cc56bf6570bbf42d6cf797d82bb6705707' 
  AND token = '6UHe1UuRwbz9ChKLtciI4iAh0M+qutCalIjYyx47Vpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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