SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b3d289b49ef34ca300d084a1905fa75c607eb6bafff159cca4d5d8bf0cca1c2' 
  AND token = 'qM7IVsXytT0sG9FT93T2CRyWNKvUsxbSnVoI22O1Fks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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