SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5688dde6e427bef4ad2b568ab1d34eae607576a2442b288cac37b09aa0025bc7' 
  AND token = 'vJ3X3kwZnJHH/LKLce6+FL72AU1Ff+9Qbg5aBKsPP6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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