SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66bbf87ee1aa7492bac352bd2d54132a3ac86485f9f42e1eeb387f45ef5c2331' 
  AND token = 'qqpyt9VVSEoTbPMCRvTpHQvhDU5QZWqbLc+ecwzJAuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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