SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05bdb44380e83dff93239d11e601ffc984719606e600664cd378a5e0725e42fb' 
  AND token = 'K0pG+I3aq/dJsApqkmiYCkE0w9kZAvTNG1cuw2oxy6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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