SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2259d323ffbd7f05ef6237d5b53019732c8212d263874f86e66f44106465afc9' 
  AND token = 'vDoi19jG66SZmKpux9I4HExVHYek9x4A1le40jXYERI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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