SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '792240f6d34115f8b36ecb096240dc3139c5d231bdf1c9f32369e30c53f1c454' 
  AND token = 'c6tdXL6x/4t9++zU69zW4IIwm2IJp6mRAENeYQOvDoQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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