SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09cb933cefb022cfbb7698ee660c62c50b2bdb86910d91889dbe02e0cc548b50' 
  AND token = 'BxkihErWc2Wviy0uHjQPXV0vDbYeRwj+qLEZUQLBWs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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