SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '04b7e739b3affbbb36048dc43c447a293506ad0082e964875d842988c5065d53' 
  AND token = 'nMtUam8oP7g+L3iiziKGuxmfCItGeKhtE3P39vsslpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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