SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd25a5a37d78ac6182abd460f96841aa666d7bd6dc2abd004013705f0c314f32' 
  AND token = 'ic6Mbo/xmRd4br1suSDa/baEEtMPkJUBUh+/aaRR6s0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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