SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d4e0789fb292d79bde2b05bd12e2df3b0cf1182b6654134e9097c8fb4c4490b' 
  AND token = 'ULwaogoLsJ3ploJkKSpjT2RwT4LqKfZqCfH+/jxciy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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