SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b17e854c4720fbe0d66f6b48e65d5c94645bf5ecea7ee115b5f29fabc1331f4d' 
  AND token = 'TGglhMlr4BxpmETVWshQZf+0rgpjXgBOOfDoYpORZps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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