SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdbcd387a5932de75a4db0f0f0081e157f2385589b0327fc705cc0e1ef619638' 
  AND token = 'Mw//a0nu6CeRbS8vqkdCN/ZUFYXtE8F9vwRPAMBsxwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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