SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b80abc635c07197b276d67451dcc2145013cd57029f9c9aa4d57dd790406c742' 
  AND token = 'UBKLtoLJRLvufcWkeHzHcjWzannEzSov+ewZFe5EvzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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