SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e16229d6e30480802a98325626060c461d9f1c6293bdc0b27a41315fc7d9181' 
  AND token = 'zKdD9ZSzuuU2wBZ3Wf1xg+t/lQwmdUYKzq2CghCBNmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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