SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4b82edc97579badd99dedc5fed46601482d7153c20296e672aa523d4b29a4f5d' 
  AND token = 'hZpV8jEJMyyB6hbrXSigYHhL+mReTrTFfAfbkS4mDLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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