SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '387b66f077a62ce0d8a8236e34330c2633812a4853b7c317bf53552b76182b93' 
  AND token = 'OB3UvCAAZ5mgwjaBZ2U6Ut268sp28JnSC7RjTcly3SI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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