SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e67dd04936f50562561565796b411c8a55699438c06972251d3b147135d5599d' 
  AND token = 'IPtKfdbY2OBRWfKwG/+EIXwCUw5iKWyhSzJ12yAwkZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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