SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1eb3b5093272171ead3bfed8cea5c497a21f7b6e13a8dfa6e3cafdceb9a31aad' 
  AND token = 'x8NkYgqj48TD0gZ1Q1yJIB2S4YHCxmSzseOFQ/10Wvs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}