SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dd2bfb38c24f090d32a49570fdcd34c66518d228a13605ece3d1dac4d2d1767' 
  AND token = 'RvXI6wdvq+mC5xtkn2MgGqqFTpnY4csKCObYnOAv0pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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