SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70e0088d4cd44ea1e2be46663e9f90666048b0739abd8b3682f10a322ed64454' 
  AND token = 'f8Kf3CoJLSWud/dNS/jmVuOvZKy4lFD7/UrCnjROCHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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