SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14ff641182c80e5d8a6604eb47e9422d90ab91984bf66f8d4e0523189ab2f94e' 
  AND token = 'kS4YRoNcuP6YzvffhlZ/sbDfVn6KGFqRuWtvuuCfV08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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