SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '714c203cabe5c36421cf880bb06f93b901f5e5f530621a1a14b390f23898116a' 
  AND token = 'xNNozTG1Lsf3eTU9pQlRsyB68y77QXQCgqn+iElV5JM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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